If by electric fence you mean one of those underground fences, I wouldn't recommend it. For one thing, they're more expensive than the livestock fencing JeanK mentions (T-posts and wire mesh fencing is about the cheapest fence you can get, at least around here, and it's easy to install yourself as well as being easy to remove should you want to install a nicer fence). They're also unreliable. Your dog may learn to stay away for the most part, but if something really triggers her prey drive or something, she may be over the boundary before she even registers the shock. I used to work in some neighborhoods where most fences were against the HOA (trying to preserve a natural mountainous look I guess) and I can't tell you how many dogs I saw on the street wearing Invisible Fence collars. And the worst part is then they can't even get back into their yards, because the stimulus that excited them enough to forget their boundary is gone and when they try to cross back over, they get shocked. Plus, it doesn't protect against other dogs, people or natural predators that might pose a threat to your dog. IMO fences are as much to keep trouble out as they are to keep your dog in.

Even if you're talking about a tape fence like are used for livestock, I'd recommend against it. They're cheaper than even a wire mesh livestock fence, but they won't keep dogs in or out. We used them for livestock and my dogs crossed over them easily, simply learning quickly not to touch the wire/tape but still sliding through it or jumping over it.

My best recommendation would be pricing fencing supplies at your local farm and ranch supply store. Tractor Supply Company is a decent chain store; otherwise, just look in the phone book under "livestock-feed and supply" or search online for "[your city] livestock supply." T-posts are a couple of bucks each; wire mesh fencing depends on what you want, but since you're buying for a dog rather than horses you can go for pretty cheap stuff (the more expensive stuff tends to be coated or otherwise safety-treated since horses are great at injuring themselves on fencing); and then you just need a T-post driver and some wire (either stuff you clip yourself and tie, or hangers) to attach the fence to the post. It's really easy and inexpensive as far as fences go, and since as I said it's also easy to remove (if a bit of work to dig out the T posts), you can even fence off a small area just to let her out in while you're down. Around here it would be very easy to make a decent-sized run for a dog with livestock fence for $100 or so, less than $100 if you've got the T-post driver or a sledgehammer you can use already.

If a fence isn't an option at all, I'd work on training her to climb on a platform outside. If you can hang the tie-out on a hook or something that you can reach, and train the pup to climb on a platform you can also reach, you might still be able to make the tie-out work.